Safety device for blasting caps



May 24 1949 J. YuRlcK Erm.

SAFETY DEVICE FOR -BLASTING CAPS Filed Oct. 4, 1946 Patented May 24, 1949 s .PATENT asics SAFETY DEVICE FOR BLASTING CAPS Joseph Yurgsk hamokin and Francis J. Ynrick,

Application October 4, 1946, Serial No. 701,274

This invention relates to a safety device or housing for blasting caps so that they are guarded against being detonated during the tam-ping operation when the explosive, such as dynamite, is being applied to a blast hole and duringdhe time the tamping operation is proceeding which will pack the charge, as is usually done in such operations.

Itis an object of this invention to provide a case in which the cap is installed, said case having a cavity into which the end of the cap projects slightly, it being the intention of the inventors that the said cavity shall be supplied with a priming charge of dynamite orthe like, which, when it explodes, will cause the firing of the blasting charge which may be in immediate contact with the case, it being understood that the case has apertures through which ilre from the priming. charge escapes to the explosive charge. By reason of the protecting case, the tamping operation cannot result in pressure on or jarring of the cap which otherwise would and often has resulted in a premature ignition of the blasting charge.

A. further object of this invention is to provide a case and cap which, when assembled, may be regarded as an article of commerce, readily available for use and in condition for use except for the installation of the priming charge; and it is furthermore thel purpose of the inventors to provide a case of the character indicated having capacity for holding two caps and their conductors, making a more certain operation, for if one cap is impaired and does not function, the other cap4 may be electrified.

A stillffurther object of the invention is to provide a device of this character comprising comparatively few, inexpensive parts which have proven emcient and satisfactory in use.

With the foregoing and other objects in view, the invention consists in the details of construction, and in the arrangement and combinationof parts to be hereinafter more fully set forth and claimed.

In describing the invention on detail, reference will be had to the accompanying drawings forming part of this application, wherein like characters denote corresponding parts in the several views, and in which- Figure l illustrates a sectional view showing a blast hole and a device embodying the invention applied thereto;

Figure 2 illustrates a sectional view on the line 2 2 of Fig. 1;

4 claims. (o1. 10a-2s) Figure 3 illustrates a view in elevation of the A case, showing the cover in section;

y Figure 4 illustrates a view in elevation, showing the opposite side of thefdevice shown in Figure 3;

Figure 5 illustrates an exploded view of the case, cover and cap, omitting the conductors to the cap;

Figure 6 illustrates a sectional embodying a modification where two` caps are employed;

Figure '7 illustrates a line 'I-1 of Fig. 6; and

Figure 8 illustrates a view in elevation, partly in se'ction, showing the cap interposed between explosive charges.

In these drawings4 l0 denotes the blast hole in a wall of material ll, such as coal, and, in

sectional view on the practice, a plurality of explosive charges I2' are lodged in the blast hole, the said charges usually being dynamite. After the explosive charge is installed, a case I3 containing a detonating cap I4 is lodged in the hole against the explosive charge. The case has a channel l5 in which the cap is lodged, and the cap has :electric conductors i6 connected to it, the said 'conductors, in the present embodiment, being extended transversely of the end of the case in a channel I1 and longitudinally thereof in a longitudinal channel i8, so that the conductors may be extended to a location outside of -the hole and to a safe distance therebeyond where they can be electried for detonating the charge. The case has a cavity i9 in its end enclosed by an apertured cover 20, and it is intended that the fire from a priming charge 2l shall escape through the apertures 22 of the' cap to the explosive charge in the bore or hole in the coal, rock, or the like, to be blasted.

In the modification shown in Figure 6, the case 2t has provision for housing two of the detonating caps such as |14 with their accompanying electric conductors for detonating them, and the two detonating caps project intoa cavity in one end of the case, which cavity may contain the .priming charge, and the case has a cover 24 with apertures for the escape of iire from the priming charge so that the explosive charge will be iired; and furthermore, in Figure 8 a modied arrangement is shown in which a detonatlng cap and the encasing member is interposed between explosive charges such as i2, and when the cap s detonated, ilre from the priming charge will travel in two directions from the ends of the case so that the dual charges will be practically view of a case 3 simultaneously exploded. In all of the installations of the explosive charges. packing bagsI 25 of encased earth or the like are lodged in the hole and properly tamped so that proper resistance to the explosion is provided and the force of the explosion will not blow out of the hole but will serve to exert lateral force for dislodging or breaking up the coal, rock, or the like.

While in the specification the terms case and housing have been employed as referring to the member I3, either such term will appropriately deiine what applicants have provided as a safety guard for the explosive cap to prevent premature explosion, and it is to be understood that the member i3 and the covering therefor may be of any appropriate material such as wood, gutta percha or plastic composition.

We claim:

1. A safety device for blasting caps adapted to be used with an explosive charge comprising a housing having an end closure with apertures therein. the said housing being provided with a recess adjacent said apertured end for receiving a priming charge, and the apertures being in communication with said recess. a seat extending longitudinally of the housing and merging with said recess, a detonating cap disposed within said seat, a channel communicating with and extending axially of said seat, electric conductors extending through said channel and being attached to said detonating cap for igniting said priming charge whereby re from the primer escapes from said housing through the apertures for detonating the explosive charge.

2. A protector according to claim l in which the cap is lodged in a seat in the housing, and electric conductors extend approximately axially to the exterior of the housing, the housing having a lateral channel through which the electric conductors extend, and a circumferential groove on the housing in which the said conductors are secured so that the housing, cap and conductors produce an article of manufacture in which the' parts are assembled for use.

3. A device as specied in claim 1 in which two caps project into said recess and an electrical conductor secured to each of said caps.

4. A safety device for blasting caps adapted to be used with an explosive charge comprising a housing having an end closure with apertures therein, the said housing being provided with a recess adjacent said apertured end for receiving a priming charge, andthe apertures being in communication with said recess, a seat extending longitudinally of the housing and merging with said recess, a detonating cap disposed within said seat, a channel in said housing in communication with said longitudinally extending seat, electric conductors extending through said channel and being attached to said detonating cap for igniting said priming charge whereby nre from the primer escapes from said housing through the apertures for detonating the explosive charge.

JOSEPH YURICK. FRANCIS J. YURICK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,558,784 Bleecker Oct. 27, 1925 2,300,225 Johnson Oct. 27, 1942 2,330,232 Moat et al. Sept. 28, 1943 2,340,695 Rothrock Feb. 1, 1944 2,358,795 Djidics et al Sept. 26, 1944 2,377,151 Huber May 29, 1945 

